the B17 was only capable of carrying 2x2000lbs (although it could squeeze in a a pair of 1000lbs as well)
That's the conclusion I've come to. I know the bomb-rails are slightly tapered with more distance between them at the lower end. Pictures show a 2000 lb bomb fitting snugly at the bottom (fin width 23 inches) but the 4000 lb Light Case has a thumping big fin width of 47.62 inches. It's also 9 ft 9 inches long.
